1,2,3,4,5,6,7,8,9,0, the sum of two three digits is equal to a four digit number, but the number cannot be repeated Who knows, please reply, urgent

1,2,3,4,5,6,7,8,9,0, the sum of two three digits is equal to a four digit number, but the number cannot be repeated Who knows, please reply, urgent

849+357=1206

Use 1, 3, 5 and 7 to form two two digit numbers. If you want to make the product maximum, which two numbers should be and make the product minimum? Please write the formula

If the two numbers can't be repeated, the bigger one is 57 × 53, the smaller one is 13 × 15, and the biggest one is the multiplication of the two largest two digits. The bigger the product, the smaller one will be

Use 4 507 8 five digits to form the product of two digits and three digits. The biggest formula is? Mainly the method

840*75=63000

Dynamics
For an object resting on a horizontal plane, the mass m = 4kg, the dynamic friction factor μ between the object and the plane is 0.1, and the object is subjected to an oblique upward tension f = 10N at an angle of 37 ° with the horizontal plane. After 4S, the tension is withdrawn, and the total displacement of the object from starting to stopping is calculated?

At the beginning, the resultant force is f = 10 * cos37 -- μ (mg-10 * sin37) = ma = 10 * 0.8-0.1 (40-10 * 0.6) = 4.6
a1=1.15 v=4a1=4.6
First, accelerate evenly for 4S, then decelerate evenly to rest
a2=--μmg/m=μg=--1
x1=0.5a1*4*4=8a1=9.2m
2a2x2=0-4.6*4.6
x2=10.58m
The one upstairs said it very well. It's estimated that he hasn't learned the kinetic energy theorem yet
x=x1+x2=19.78,m

Two people with the same height and weight wear the same shoes on the same level ground, and try to force the other side to retreat by using a light pole. Suppose that the thrust of a and B on the pole are F1 and F2 respectively. The included angles of a and B's body deviation from the vertical direction due to forward tilt are A1 and A2 respectively. The greater the tilt a is, the lower the end position of the hand and the pole will be at this moment. If a wins, it will be better
A. F1 = F2, A1 is greater than A2
B. F1 is greater than F2, A1 = A2
C. F1 = F2, A1 is less than A2
D. F1 is greater than F2, A1 is greater than A2
But I don't think F1 and F2 are forces and reaction forces. They are all caused by human action, not by direct interaction between two people. So we can only say that the force exerted by the rod is equal to F1 and F2. Moreover, if F1 and F2 are equal, the rod will not move, how can people move?
I can understand that the static friction of a is greater, so can we deduce F1 > F2 from this conclusion?

Let me analyze this problem for you. First of all, you need to build a suitable physical model. If a wins, it means that a's center of gravity will be lower, that is, A1 should be greater than A2. Only in this way can we ensure that a's force has a downward component and B's force has an upward component. In this way, the maximum static friction force a can bear will be greater than that B can bear

A problem of physical mechanics
A slope with rough surface is placed on a smooth horizontal ground, and the slope angle is θ. A slider with mass m can slide along the slope at a constant speed. If a horizontal thrust of unknown magnitude is applied on the slider to make it slide up the slope at a constant speed, in order to keep the slope stationary, the horizontal thrust for the slope is calculated

First, we find that the component of gravity along the downward direction of the inclined plane is mg × sin θ. Because it can slide at a constant speed, the object is in a state of equilibrium, and we can get that its friction is equal to the component of gravity along the downward direction of the inclined plane, which is mg × sin θ = mg × cos θ × U (dynamic friction factor), and u = sin θ / cos θ

Calm English words

Peace is peaceful

What are the quiet English words

If the environment is quiet, use "quiet / peaceful". If you are silent, use "silent". If you are calm, use "calm"

What is a word to translate "dead of night" into English?

silence in the deep of the night

English: which English word is used to describe inner peace?

Calms are often used to describe someone who is calm when he meets something at a certain time. Peaceful is used to describe someone's nature and his heart is always peaceful. You should choose peaceful according to what you say